Pediculus humanus capitis (head lice) is a parasite that can affect humans & can betransmitted two ways. The most common is direct person to person contact. The second way is vector transmission – from a contaminated object to a person.
...Read more

2

If no live lice:
If you do not see any live "crawlers" you are ok to be in a public place. Nits are the eggs, if you apply permethrin dose twice 2 weeks apart that should take care of the lice if they hatch
...Read more

3

Not always. Depends :
On pediculicide used. The most effective approach is to retreat lice. The reason is that not all pediculicides kill the eggs. It is best to retreat in the window when the eggs have hatched into nymphs but are not yet hatching new eggs. There are however, some pediculicides which are strongly ovicidal.
...Read more

4

Fine tooth comb:
Most otc products come with a fine toothed comb used to remove the nits from the hair.Some find that soaking the hair in vinegar will loosen the nits & make them easier to separate.
...Read more

6

Various methods:
Many find soaking the hair with a stout vinegar will loosen the eggs from the hair.A nit comb (fine tooth) can then remove them a bit easier. Several treatments may be needed.
...Read more

8

Egg encasements:
Human lice are mature by 10 days of age and can start laying eggs thereafter. They do so at the level of the scalp within a hard shell that incubates the egg until the new lice emerges.The nit, is attached to the hair by a glue like material that is resistant to easy separation. Mild acidic washes like vinegar can help dissolve the glue and help with removal along with a fine tooth comb.
...Read more

9

Maybe,maybe not:
Nits mean the presence of adult lice. The duration of the infestation can be estimated by the distance of nits from the scalp.Hair grows ~.5in/mo, so if .5in high in hair they were around for a month.You will generally never be able to see the lice unless you shave off all the hair they hide in. They ay or may not be gone.If nits re-appear, they remain.
...Read more

10

Not by the number...:
...But by their location on the hair shafts. A head louse will attach her eggs (which is what nits are) to hair shafts at the point where they come out of the skin. As the hair grows, the nits move up from the scalp surface. Hair grows about 1 inch per month, on average - so if the nits are a half-inch away from the scalp, lice have been present for about 2 weeks; an inch away, 4 weeks; and so on.
...Read more